Engine carburetor with throttle control lever

ABSTRACT

The throttle valve in the carburetor of an internal combustion engine is manually controlled by a lever pivotally mounted directly on one side of the body of the carburetor at a location beneath the air cleaner on the carburetor air inlet duct.

United States Patent Charles Robert Peifer Pewaukee, Wis.

Jan. 2 3, 1970 Oct. 19, 1971 Briggs 8: Stratton Corporation Wauwatosa, Wis.

Inventor Appl. No Filed Patented Assignee ENGINE CARBURETOR WITH THROTTLE CONTROL LEVER 5 Claims, 5 Drawing Figs.

U.S. Cl 123/103 R, 74/5 3 1 Int. Cl ..F02d 11/08, 605g 5/06 Field of Search 267/DIG.

References Cited UNITED STATES PATENTS 4/ I 927 Norviel 74/53 1 7/1950 Suska 74/531 X 11/1950 Brown etal 123/103 BX 11/1910 Brownetal 123/103BUX 5/1960 Eberline 123/103 B X 4/1968 Hanson et a1. 261/65 UX 10/ 1 968 Brilando et al. 74/491 6/1969 Nelson et al. 26l/DIG. 68

Primary Examiner-Wendell E. Burns Attorney-Ira Milton Jones ABSTRACT: The throttle valve in the carburetor of an internal combustion engine is manually controlled by a lever pivotally mounted directly on one side of the body of the carburetor at a location beneath the air cleaner on the carburetor air inlet duct.

PATENTEBucI 19 I911 SHEEI 10F 2 INVENTQR UZ-LEPZE HUZJEIZ Pmfer' BY ATTORNEY PATENTEUnm 19 I97! SHEET 20F 2 38 huvswroa E rZes Hubert FE /"E2" ATTORNEY ENGINE CARBURETOR WITH THROTTLE CONTROL LEVER This invention relates to small govemor-controlled internalcombustion engines, and has more particular reference to carburetors for such engines.

An intemal-combustion engine of the type herein concerned has a carburetor with a tubular body that extends horizontally along the top of a gasoline tank from which the engine is supplied with fuel. Air is admitted into one end of the tubular carburetor body through an upstanding air inlet duct, for admixture with the fuel in quantities sufficient to form a gaseous fuel mixture best suited for combustion.

As is customary, an air cleaner is mounted on the air inlet duct, and the carburetor is substantially sandwiched between the air cleaner and the gasoline tank. The speed at which the engine runs of course, is determined by the setting of a throttle valve in the interior of the carburetor body; and the shaft carryingthe throttle valve is adjustable manually, and also automatically by a governor in a manner well known in the art.

It is the purpose of this invention to provide improved throttle control means for manually adjusting the governor setting by which the throttle valve in the carburetor of an internalcombustion engine is regulated.

More particularly, it is an object of the invention to provide for suchadjustment of the governor setting by means of a manually operable hand lever mounted directly on one side of the carburetor body. In a broad sense, this objective was achieved hitherto, in U.S. Pat. No. 3,376,890 issued Apr. 9, I968, to R. A. Hanson et al. In Hanson et al., however, the carburetor inlet duct projected upwardly into a large hole in the hand lever to provide a bearing supporting the lever for swinging movement about a vertical axis. This mounting of the lever was subject to the objection that the lever was not positively held assembled with the carburetor at times when the air cleaner was removed, with the resulting danger of displacement of the lever from its pivotal support.

Hence, it is a further object of this invention to provide a carburetor with a throttle control lever which is so mounted on the carburetor body as to be completely unaffected by removal of the air cleaner from the inlet duct thereof.

In a specific sense, this invention provides a carburetor for an internal-combustion engine, wherein the carburetor body has a boss on one side thereof, cast integrally with the body at a location below the mouth of its air inlet duct, and upon which the throttle control lever is mounted for pivotal motion about a horizontal axis near the junction of the axes of the air inlet duct and the tubular carburetor body.

With these observations and objectives in mind, the manner in which the invention achieves its purpose will be appreciated from the following description and the accompanying drawings, which exemplify the invention, it being understood that such changes in the specific apparatus disclosed herein may be made as come within the scope of the appended claims.

The accompanying drawings illustrate one complete example of the embodiment of the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

FIG. 1 is a perspective view illustrating that portion of an internal-combustion engine having the gas tank, carburetor and air filter mounted thereon;

FIG. 2 is a perspective view somewhat similar to FIG. 1 but with the air cleaner removed;

FIG. 3 is a view similar to FIG. 1 but showing the various components in side elevation;

FIG. 4 is a plan view of the throttle control mechanism with the air cleaner removed; and

FIG. 5 is a fragmentary sectional view taken on the line 5 Sin FIG. 3, and at an enlarged scale.

Referring now to the accompanying drawings, the numeral 5 generally designates a small internal-combustion engine, only a portion of which has been shown. The engine is provided with a carburetor 6 having an elongated tubular body 7 that extends generally horizontally along the flat top 8 of a gasoline tank 9. The carburetor 6, which is of die-cast construction, has an integral flange 10 at one end of its body to provide for securement of the carburetor to the engine.

The gasoline tank 9 is secured to the underside of the carburetor in a well-known way, and the body 7 of the latter extends along the top 8 of the tank from the flange 10 at one end to an upstanding air inlet duct 12 at its oppositeend. A conventional type of air cleaner 13 is mounted on the upper end of the air inlet duct 12, as by means of an elongated screw 14 passing downwardly through the cleaner.

A throttle valve, not shown, is mounted in the body 7 of the carburetor on a shaft l5for turning movement about a vertical axis located intermediate the air inlet duct and the flange 10 (see FIG. 4). The throttle valve is part of an assemblage including the throttle shaft 15 and an externaldisc 16 at the top of the carburetor body. The stiff wire 17 of a governor mechanism, not shown, is connected to'the disc as at 18, and a tension spring 19, which has one end connected with the governor wire acts through'the latter in a direction tending to advance the throttle'in the clockwise direction as seen in FIG. 4, toward a full-open position defined by the engagement of a lug 20 on the throttle disc with an abutment 21 onthe carburetor body.

When the engine is in operation, however, the governor acts in opposition to the spring 19 in the conventional manner, to maintain engine speed in accordance with the setting of a lever 23 to whichthe other end 24 of the tension spring 19 is secured. The lever 23 is freely pivotally mounted as at 25 on the side of the carburetor body for rockingmotion about a horizontal axis normal to that of the body, and intermediate the axis of the throttle shaft and the mounting flange 10.

The angular position 'of the lever 23 on its axis is, in turn, defined by the setting of the throttle control lever 27 of this invention, which is connected to the lever 23 by a stiff wire link 28. The throttle'controllever 27 is mounted on a boss 30 on the outer'en'cl portion of the carburetor body, adjacent to its air inlet duct 12, and at the same side of the carburetor body as the lever 23. As'best seen in FIG. 5, a screw 31 threaded into the boss 30 holds the lever assembled with the carburetor body. A bushing 29 encircling the screw and passing through a hole in the lower arm 32 of the lever mounts the lever for rocking motion about a horizontal axis near the junction of the axes of the air inlet duct 12 and the tubular body 7 of the carburetor. The arm 32 of the lever extends downwardly from the bushing, and it has downwardly convergent side edges 33 and an outer end portion 34 which is offset away from the side of the carburetor to provide for attachment of the link 28 thereto, as at 35. v

The head of thescrew 31 bears against a flange 43 on the outer end of the bushing to'hold the inner end of the bushing in abutting engagement with the face of a stop plate 39 overlying the boss 30. The axial'length of the bushing is such as to accommodate under its flange 43 the combined thicknesses of the lever arm 32 and of a spring washer 44, which latter overlies the outer face of the arm 32. v

At a slight distance above the head of the screw 31, the lever has a substantially horizontal portion 36 which extends along the underside of the air cleaner [3, outwardly away from the carburetor body, and joins with an upstanding arm 37 of the lever. The arm 37 extends upwardly alongside the air cleaner to a handle 38 on the upper end of the lever, which also extends outwardly in the same direction as the intermediate lever portion 35.

The handle 38 is preferably disposed adjacent to the top of the air cleaner [3 which can have suitable legends applied thereto for cooperation with the handle in indicating to an operator where the throttle control lever must be set to stop and start the engine, at the extremes of rocking motion of the lever, and where to obtain operation of the engine at any speed between slow and fast speeds. I

The limits of rocking motion of the throttle control lever 27 are defined by the stop plate 39, which is confined between the lower arm 32 of the lever and the boss 30 upon which it is pivotally mounted. The stop plate has a hole to receive the shank of the screw 31, and it has ears 40 which embrace the boss 30 to prevent it from turning motion on the bushing. Other cars 41 struck outwardly from the opposite side portions of the stop plate provide abutments which are engageable by the side edges of the lower arm 32 of the throttle control lever to define its limits of motion, namely, its start and stop positions.

The throttle control lever 27 must be capable of remaining in any position of adjustment it is placed in by an operator, against the tendency of the tension spring 19 to rock the lever in the counterclockwise direction as seen in FIG. 3. It is for this purpose that the spring washer 44 is confined between the outer face of the lever arm 32 and the flange 43 on the bushing 29, in encircling relation to the latter. The spring washer 44 is held by the head of the screw 31 against the lever arm 32 with an unvarying degree of pressure that produces sufficient friction in thepivotal connection between the throttle control lever and the carburetor body to require a definite manual effort on the part of the operator to adjust its angular position on the bushing 29.

As is conventional, the throttle control lever has a choke position, when in its clockwise limit of motion with respect to FIGS. 1 and 3. When moved to that position, the throttle control lever imparts counterclockwise motion to the freely pivoted lever 23, and the latter moves to-and-past the highspeed throttle setting to collide with an abutment 45 on a choke rod 46, to effect shifting of the rod lengthwise'to the left. The rod 46 has a motion-transmitting connection with a choke handle 47 to cause reduction of airflow through the air inlet duct 12 at times when the handle is moved outwardly, to the left of its normal position seen in FIGS. 3 and 4.

From the foregoing description, together with the accompanying drawings, it will be apparent that this invention pro vides a manually operable throttle control lever and an improved mounting therefore by which the air cleaner can be removed whenever necessary without risk of displacement of the throttle control lever from its proper position on the carburetor.

Those skilled in the art will appreciate that the invention can be embodied in forms other than as herein disclosed for purposes of illustration.

The invention is defined by the following claims.

lclaim:

l. A carburetor having a governor controlled throttle valve,

characterized by:

A. a tubular body containing the throttle valve, and having means thereon at a first location defining an air inlet duct the axis of which is substantially normal to that of the tubular body;

B. a governor control lever pivotally mounted on the body at a second location;

C. means on the body projecting from one side thereof adjacent to said first location defining a pivot disposed on an axis substantially normal to the axes of the body and of the air inlet duct;

D. a throttle control lever having an arm in juxtaposition to said side of the body and rockably mounted on said pivot;

E. and a throttle valve adjusting link connecting the governor control lever with the throttle control lever.

2. The carburetor of claim 1, further characterized by:

A. said air inlet duct being disposed on an upright axis adjacent to one end of the tubular body;

B. and said'means projecting from one side of the body to define a pivot comprising 1. a boss on the side of the body adjacent to the inlet duct, 2. and a screw having a portion threaded into the boss and projecting therefrom.

3. The carburetor of claim 2, further characterized by:

A. an air cleaner mounted on the air inlet duct;

B. and said boss being located under the air cleaner and projecting a substantial distance from the side of the carburetor body so as to help hold an upright portion of the throttle control lever from contacting the side of the air cleaner.

4. The carburetor of claim 2, further characterized by:

A. a head on the screw overlying the outer face of said lever arm;

B. and a spring washer encircling said screw and confined under its head, to frictionally but yieldingly resist rocking motion of the throttle control lever.

5. The carburetor of claim 2, further characterized by:

A. a plate confined between said boss and said lever arm and held in place by said screw;

B. means on the plate cooperating with said boss to prevent rotary motion of the plate about the axis of the screw;

C. and stop abutments carried by said plate and engageable by opposite side edge portions of said lever arm to define the limits of rocking motion of the throttle control lever. 

1. A carburetor having a governor controlled throttle valve, characterized by: A. a tubular body containing the throttle valve, and having means thereon at a first location defining an air inlet duct the axis of which is substantially normal to that of the tubular body; B. a governor control lever pivotally mounted on the body at a second location; C. means on the body projecting from one side thereof adjacent to said first location defining a pivot disposed on an axis substantially normal to the axes of the body and of the air inlet duct; D. a throttle control lever having an arm in juxtaposition to said side of the body and rockably mounted on said pivot; E. and a throttle valve adjusting link connecting the governor control lever with the throttle control lever.
 2. The carburetor of claim 1, further characterized by: A. said air inlet duct being disposed on an upright axis adjacent to one end of the tubular body; B. and said means projecting from one side of the body to define a pivot comprising
 2. and a screw having a portion threaded into the boss and projecting therefrom.
 3. The carburetor of claim 2, further characterized by: A. an air cleaner mounted on the air inlet duct; B. and said boss being located under the air cleaner and projecting a substantial distance from the side of the carburetor body so as to help hold an upright portion of the throttle control lever from contacting the side of the air cleaner.
 4. The carburetor of claim 2, further characterized by: A. a head on the screw overlying the outer face of said lever arm; B. and a spring washer encircling said screw and confined under its head, to frictionally but yieldingly resist rocking motion of the throttle control lever.
 5. The carburetor of claim 2, further characterized by: A. a plate confined between said boss and said lever arm and held in place by said screw; B. means on the plate cooperating with said boss to prevent rotary motion of the plate about the axis of the screw; C. and stop abutments carried by said plate and engageable by opposite side edge portions of said lever arm to define the limits of rocking motion of the throttle control lever. 